Electromagnetic Spectrum/Transcript
Transcript An animation shows purple and orange squiggly lines writing across a white background. Text reads: The Mysteries of Life with Tim and Moby. Tim opens a microwave and removes a bowl of soup. TIM: Mmmm! Chicken mushroom! A robot head and arm belonging to Moby descend from the top of the screen. Moby drops a piece of paper into Tim’s soup and then moves back up out of shot. TIM: Dear Tim and Moby, what is the electromagnetic spectrum? Signed, Winston. An image shows Tim's hand holding a typed letter. TIM: The electromagnetic spectrum is just the name for a bunch of types of radiation, organized by the amounts of energy they carry. Moby unrolls a poster onto a wall. The poster is titled, “Electromagnetic Spectrum.” Under the title is a wide rectangle filled mostly with different shades of gray from darkest on the left to lightest on the right. In the middle is a narrow strip with the colors red, orange, yellow, green, blue and purple from left to right. MOBY: Beep? TIM: No, no, it doesn't have to be from radioactive material, like plutonium, necessarily. Tim addresses the camera. TIM: Radiation is any movement of energy through space. You can think of this radiation as a wave made up of moving electrical and magnetic fields; or you can think of it as a stream of particles called photons. An animation shows two side-by-side images. On the left, two squiggly lines, one purple and one orange, move down the screen and crisscross repeatedly. On the right, a line of small yellow circles move down the screen. Text reads: photons. TIM: EM radiation is kind of... indecisive. Sometimes it behaves like a wave, sometimes like particles. Starting with the lowest energy level, the seven types of EM radiation are: radio waves, microwaves, infrared light, visible light, ultraviolet light, x-rays, and gamma rays. An animation shows a vertical, rectangular diagram with seven shaded sections. From bottom to top, the sections change from the dark to light. In the middle of the diagram is a narrow rectangle with a rainbow pattern that includes strips of red, orange, yellow, green, blue and purple. The bottom of diagram is labeled “long wavelength” and the top of the diagram is labeled “short wavelength.” Text appears sequentially from bottom to top: radio waves, microwaves, infrared light, visible light, ultraviolet light, x-rays, and gamma rays. The “visible light” label aligns with the rainbow pattern in the diagram. TIM: Radio waves are used to transmit radio and television signals. A transmission tower is shown. An animation shows a series of concentric circles being emitted from the top of the tower, growing wider until they disappear. Text reads: radio waves. TIM: AM radio uses low-energy waves, FM radio uses medium-energy waves, and TV uses high-energy waves. Three animated waves are shown moving across the screen from left to right. At the top is an orange wave with widely spaced curves, labeled “Upper A Upper M.” Below this is a beige line with more tightly spaced curves, labeled “Upper F Upper M.” Below this is a light blue line whose curves are very close together, labeled “Upper T Upper V.” TIM: Cell phones use radio waves, too. The home screen of a smartphone is shown on the left side of the screen. TIM: And stars in space can also emit radio waves. Stars, represented by white dots on a black background, are shown on the right side of the screen. TIM: Microwaves are used in microwave ovens and airplane radar systems. An image of a microwave oven on a counter top is shown. Above this, and animation of an airplane moving against a light blue background is shown. Text reads: microwaves. TIM: In the oven, microwaves heat up the water molecules in your food. An animation shows five clusters of pink spheres slowly moving around a blue background. Each cluster is made of one large central sphere and two smaller spheres connected to the central sphere. TIM: With radar, microwaves are reflected off an airplane and sent back to the radar system to pinpoint the exact location of the plane. An animation shows a dark circle divided into 4 quadrants. A green radius moves clockwise around the screen, leaving a blurred green trail behind it. There is one point on the screen in the upper right quadrant that lights up and then dims when the sweeping radius passes over it. Text reads: radar. TIM: Infrared rays are often produced when an object radiates heat. Tim and Moby are sitting on a couch addressing the camera. The back of a television partially blocks the view of Tim and Moby. Text reads: infrared rays. TIM: You can’t see them, but you do feel them. A remote control uses infrared rays to send signals to your TV set, stereo, or DVD player. Tim lifts up a black rectangular device and points it at the television. TIM: Infrared radiation can also be used to take special photographs called thermographs. A blurry image of a human head, neck and upper shoulders is shown. There is a red blob around where the eyes and nose would be, and a second red blob at the mouth. Regions of orange, yellow, brown, purple, and dark blue are shown from the center of the face moving outward. Text reads: thermograph. TIM: The next type of radiation in the spectrum is visible light. Tim addresses the camera. Text reads: visible light. TIM: Thanks to special cells called cones, our eyes can perceive wavelengths of visible light as color. The screen splits, and to the right of Tim an animation of the cross-section of a human eye is shown. The cross section is nearly circular, with a small bulge in front and a small, roughly oval piece directly behind the front bulge. Part of the eye extends out from the back of the circular shape and continues off-screen. At the back of the eye, a small, yellow, arrowhead-shaped object is shown. The eye disappears and the arrowhead-shapes object rotates and grows bigger. Text reads: cones. Below this, a breakfast of toast, bacon, eggs, coffee and juice are shown. TIM: In order from lowest to highest energy, the colors are known as: red, orange, yellow, green, blue, indigo, and violet. An animation shows a vertical rectangular diagram on the left divided into seven sections. Each section represents a color, which are labeled sequentially from bottom to top: “red,” “orange,” “yellow,” “green,” “blue,” “indigo,” “violet.” Text reads: color. TIM: Ultraviolet rays occur naturally in sunlight. An animation shows a flickering sun emitting five squiggly lines. Text reads: ultraviolet rays. TIM: Fortunately, the ozone layer blocks most UV radiation from reaching the surface of the earth. The scene zooms out slightly and a portion of the earth becomes visible. The emanating squiggly lines stop at a layer that is above and concentric to the surface of the earth. TIM: In large doses, UV rays can cause skin cancer and cataracts. Tim and Moby address the camera. TIM: X-rays have a very high penetrating power. That means they can travel easily through just about anything. Tim addresses the camera. Text reads: x-rays. TIM: Doctors use small doses of them to make pictures of your bones and organs and stuff. To the left of Tim, an image of an x-ray photograph of a leg and foot shows a visible crack in one of the bones. TIM: The x-rays travel more easily through flesh than bone; that's why shining x-rays through someone onto sensitive film can make an image of your insides. Gamma rays are the most energetic waves in the EM spectrum. Tim and Moby address the camera. Text reads: gamma rays. TIM: Most gamma rays coming from space are absorbed by our atmosphere. An animation of a portion of the Earth and its atmosphere is shown. The atmosphere is illustrated as a concentric layer around the Earth. TIM: But gamma rays are also produced on Earth in high-energy reactions, such as nuclear explosions. An animation shows a light blue background above and bare gray area below. A bright flash, accompanied by an explosion sound, forms into mushroom cloud that grows larger. TIM: Gamma rays do a lot of damage when they pass through living cells. Tim and Moby address the camera. MOBY: Beep? TIM: Where does the radiation come from? Well, all matter is made up of atoms, and each atom is made up of protons, neutrons, and electrons. A diagram of an atom is shown. It contains a central nucleus represented by a cluster of closely packed yellow and orange spheres. Small blue circles traveling along three circular, concentric, gray-colored paths move around the nucleus. Text reads: atom. TIM: Electrons orbit around the proton and neutron nucleus at different levels, or shells, depending on how much energy they have. The gray paths with their blue circles begin to grow and shrink vertically, giving the appearance that they are rotating in and out of the screen about a horizontal axis. The rotation rate increases until the individual paths and circles are no long visible, and what remains is a set of three concentric, solid purple circles with the same radii as the original paths. TIM: Sometimes an electron drops from one energy level to another, giving off energy in the form of electromagnetic radiation. Periodically, a blue circle becomes visible and moves quickly from one part of the diagram to another before disappearing. One of these events is accompanied by a yellow disc that appears in the center of the diagram and moves quickly outward, growing as it exits to give the appearance it is coming out of the screen. TIM: The sun, Earth, and stars all radiate electromagnetic energy of varying strengths. Tim addresses the camera. TIM: All electromagnetic radiation moves through the universe at a constant speed of 300,000 kilometers per second. EM radiation can even travel through the empty vacuum of outer space. Stars, represented by white dots, are shown on a dark blue background. TIM: The higher the energy of the wave, the more stuff it tends to pass through. Tim and Moby address the camera, with the microwave oven behind them. Tim is holding a bowl of soup, which he slurps loudly. TIM: Ugh, my soup's cold. Moby’s hand reaches over and points into the soup bowl. Flames shoot out of one of Moby’s fingers into the soup bowl. TIM: Thanks. I was…I was kind of afraid you were going to nuke it. MOBY: Beep? Moby points to the microwave oven. TIM: No, I meant literally. Category:BrainPOP Transcripts Category:BrainPOP Science Transcripts Category:BrainPOP Engineering & Technology Transcripts